1. Field of Invention
My invention relates to a shipping box with an internal holding device, specifically to an improved way to ship a dental impression from the dental office to the dental laboratory without damaging or distorting the impression to such an extent that the appliance made from this impression will not fit the prepared tooth.
2. Discussion of Prior Art
My invention is a shipping box with an internal holding device designed to transport a dental impression (for crown or bridge work) without damage or distortion. My invention does this by suspending the impression by it's handle in mid-air inside the box using the internal holding device. Packing material is not needed.
Most dental impressions for making crowns or bridges are taken with “triple trays”. Triple trays are also referred to as bite trays, bite relation trays, 3-way trays, and dual arch trays. Triple trays are composed of a body (where the impression material is placed) and a handle (which sticks out of the mouth while the impression is being taken and is used to remove the tray from the mouth when the impression material is set). Triple trays are most often made of plastic and are flexible. Triple trays take an impression of the upper and lower arch as well as the bite all at the same time. Triple trays are made for the posterior part of the arch (FIG. 1), the anterior part of the arch, a complete quadrant, or a full arch.
Impressions for crowns and bridges are taken with a variety of impression materials—vinyl polysiloxane, polyether, silicone, and rubber base to name a few. When set, all these impression materials are flexible. Yet all have great memory when deformed and return with accuracy to their original shape. Impressions are almost always deformed to some degree simply by removing them from the mouth after they are set. Their recovery from this deformation is what makes them a great impression material. Without this characteristic crowns would rarely fit after being made from these impressions.
After removal from the mouth impressions are occasionally poured up in the office but most often are sent via the postal service or other carrier to the dental laboratory to be poured. At the present time impressions are boxed in the following manner using a traditional shipping box with an interior open space: place packing material in the bottom the box—place the impression on top of the packing material—finish filling (in some cases over filling) the box with packing material—close the lid and tape the box for shipping. If impressions are not packed properly, they can deform under pressure by compressing the packing material around the impression when the lid is closed. Allowed to remain in this deformed state for an extended period of time and under various environmental conditions, an impression may not regain its correct shape before it is poured. A crown made from such an impression would fit the die accurately but would not fit properly on the prepared tooth. My invention was designed to eliminate such a problem.
My invention consists of a shipping box with an internal holding device. The box is rectangular in length and width with two end walls, two side walls, a bottom and a lid. Unlike a standard shipping box with just an open space for the interior, the box of my invention has an interior space that is divided into a receptacle on one end for receiving an internal holding device and a suspension area on the other end where the body of the impression is suspended in mid-air (FIG. 2). These two areas are formed by placing stops on both side walls equidistant from one of the end walls. These stops run from the top to the bottom of the box and prevents the anterior displacement of the internal holding device when it is placed in the receptacle. The receptacle extends the full depth of the box and has the same length and width as the blocks of the internal holding device.
The lid of the shipping box can be removable (FIG. 3) or hinged (FIG. 4). If hinged, the lid has a front flap that folds down over the front wall. The front flap off the lid may have a tab off the front edge that inserts into a slot in the front wall to lock it closed or the front flap off the lid may have lock tabs off each side to do the same. The lid may also have lock tabs off each side (FIG. 5).
The box can be constructed of any material that is able to withstand the abuse parcels normally receive in transport. Paperboard and cellulosic or resinous material (plastic) are materials normally used for shipping boxes and either one can be used for this invention.
Cutouts may be added to the box to allow the hand to more easily place or remove the internal holding device and the impression from the receptacle in the box. Cutouts may be of any shape as long as they do not weaken the structural integrity of the box (FIG. 6).
The internal holding device will hold a dental impression securely by it handle while allowing the body of the impression to be held in mid-air. When the internal holding device is placed in the receptacle of the box, the body of the impression is held in mid-air inside the suspension area of the box and will not touch the interior walls of the box.
The internal holding device of my invention is composed of two blocks. The two blocks should be of such length and width that they fit into the receptacle in the box (FIG. 7). When placed one on top of the other the two blocks should have the same thickness as the internal depth of the box (FIG. 8). When the two blocks are placed in the receptacle, the top of the blocks should be flush with the top of the box without the lid being closed. When the lid is closed, the two blocks are secure in the receptacle and cannot be dislodged.
The two blocks of the internal holding device should be constructed of a material that can be imprinted. Polystyrene foam, styrofoam, and other similar materials imprint easily and work well as the blocks. The internal holding device depends on this imprinting of the blocks to secure the impression for transport. If the handle of an impression is sandwiched between the two blocks and the two blocks are compressed, an imprint of the handle of the impression is formed in the two blocks (FIG. 9). The two blocks are then fastened together with the handle of the impression embedded in the blocks. The two blocks can be secured together using tape, elastics, plastic ties, cord or any other device as long as the device does not hinder the placement or removal of the internal holding device from the receptacle in the box or does not prevent the closure of the lid. The two blocks with the handle of the impression embedded between them, is then slid down into the receptacle in the box. The body of the impression is positioned in the suspension area of the box, suspended so that it does not touch the sides, the bottom, or the end of the box. The lid is then closed, making sure that the lid does not touch the impression. The internal holding device with the impression is now secure in the box. The impression will not move, even if tossed about as it could be during transport The box is then taped and made ready for shipment.
All dentists have encountered this problem. The crown comes back from the lab. It fits the die perfectly but it will not fit the prepared tooth. This invention was designed to eliminate one possible cause—the deformation and distortion of the impression when boxed for transport.